Antrodiaetus ashlandensis, Cokendolpher, James C., Peck, Robert W. & Niwa, Christine G., 2005

Cokendolpher, James C., Peck, Robert W. & Niwa, Christine G., 2005, Mygalomorph spiders from southwestern Oregon, USA, with descriptions of four new species, Zootaxa 1058, pp. 1-34 : 16-17

Antrodiaetus ashlandensis n. sp.

Figs. 1 , 7 , 11 , 19–20 , 22–23 , 34 , 38–39 , 49

Type Material. Oregon (all collected in 1998 by Niwa and Peck USFS): Jackson County, Ashland Watershed, Ashland Ranger District, Rogue River National Forest: N42°85’8.0”, W122°42’24.9” (1000–1146 m elevation), 29 Sept. (3m, AMNH), 11 Oct. (male holotype, NMNH), (4 male paratypes, JCC); N42°9’50.2”, W122°42’24.9” (926–1024 m elevation), 11 Oct. (4 male paratypes, WFIC); N42°8’58.0”, W122°41’14.3” (1219–1268 m elevation), 29 Sept. (1 male paratype, JCC); N42°8’5.7”, W122°42’24.9” (1463 m elevation), 11 Oct. (1 male paratype, JCC); N42°8’5.7”, 122°41’14.3” (1317–1365 m elevation), 29 Sept. (2 male paratypes, AMNH), 11 Oct. (3 male paratypes, TTU).

Diagnosis. The separation of this species from others of the region requires examination of several characters. The combination of no cheliceral distodorsal projection or setal coat on upper ectal surface ( Figs. 19 , 34 ), having all three dorsal opisthosomal sclerotized patches separate ( Fig. 11 ), and by having a prolateral brush of macrosetae on tibia I ( Fig. 38, 39 ) will distinguish the new species from all congeners except A. pugnax and A. occultus . It can be separated from A. pugnax by not having the leg I segments of the male enlarged ( Fig. 48 versus Fig. 38 ) and from A. occultus it differs by not having the macrosetae of tibia I extending to the distal end ( Fig. 47 versus Fig. 38 ).

Etymology. The species name is based on the region of Oregon where this spider was discovered.

Distribution. Known only from Ashland Ranger District, Rogue River National Forest, Jackson County, Oregon ( Fig. 1 ).

Description. Female unknown. Male (n = 19): body large, total body length 11.4 (9.6, 11.5). Color: orangish­brown, sclerotized patches on opisthosoma more evenly brown, dark brown pigment encircling anterior median eyes and between posterior median and lateral eyes.

Dorsal shield of prosoma 5.5 (5.05, 5.85) [mean ± s.d., 5.44 ± 0.23 (n = 19)] long, 4.35 (3.9, 4.55) wide, with setae scattered sparsely over pars thoracica except very densely along lateral and posterior borders.

Opisthosoma 5.9 (4.55, 5.65) long, 4.1 (3.3, 4.15) wide; all three dorsal sclerotized patches separate ( Fig. 11 ); male genital plate with sclerotized parts divided, straight to recurved ( Figs. 22–23 ).

Chelicera with large area on upper ectal surface without setae; without distodorsal projection ( Figs. 19 , 34 ).

Palp with tibia swollen. Tibia 2.56–2.68 times longer than wide; widest in proximal third; 3.2 (3.1, 3.35) long, 1.25 (1.2, 1.25) wide. Tip of outer conductor sclerite ( Fig. 49 ) roundly pointed; not appressed to inner conductor sclerite. Tip of inner conductor sclerite well sclerotized and not curved.

Leg I ( Figs. 38–39 ) without any segment being greatly enlarged or modified with processes; femur 5.6 (5.25, 5.8) long, patella 2.2 (2.15, 2.45) long, tibia 3.75 (3.6, 3.9) long, 0.8 (0.75, 0.95) wide, metatarsus 4.35 (4.1, 4.45) long, tarsus 2.7 (2.4, 2.75) long. Tibia I with relatively dense group of prolateral macrosetae medially (not reaching distal end of segment). Macrosetae with 40.5–43.3% being ensiform: with 26 (11 ensiform) [30 (13 ensiform), 37 (15 ensiform)] macrosetae. Tibia I with 11 (7 large) [11 (7 large), 13 (8 large)] medial (not extending to distal end) macrosetae ventrolaterally, the longest seta at most about width of tibia (about as long as prolateral macrosetae). Tibia I without large heavy macrosetae ventrally; tibia and metatarsus I not swollen in lateral view; metatarsus I sinuous, without macrosetae ventrally; other setae ventrally on metatarsus I = 2 times greatest width of segment.

Wandering Activity. All 19 males were collected on 29 September (6) and 11 October (13) 1998 ( Fig. 7 ).

Comment. Antrodiaetus ashlandensis n. sp. was collected in 9 of 18 sites within the eastern Siskiyou Mountains study area. Six of the sites had previously experienced prescribed underburning.

Figures

FIGURE 1. Map of Oregon showing study areas within the Siskiyou and Cascade Mountains and a list of mygalomorph species found in each area [relief map modified from: http: // www. flag. wr. usgs. gov / USGSFlag / Data / maps / Oregon. gif (accessed 31 August 2005)]. Insert shows position of region within the USA.

FIGURE 7. Abundance of adult male Antrodiaetus spiders collected in pitfall traps from southwestern Oregon.

FIGURES 8 – 11. Dorsal view of male body. 8, Microhexura idahoana Chamberlin & Ivie (note spur on tibia I); 9, Hexura rothi Gertsch & Platnick; 10, Atypoides gertschi Coyle; 11, Antrodiaetus ashlandensis n. sp. Not to scale; see text for approximate sizes of the different species. Arrows indicate sclerotized patches.

FIGURES 16 – 21. Characters of Mecicobothriidae and Antrodiaetidae. 16, Hexura rothi Gertsch & Platnick (male: 16, ventral view of spinnerets). 17 – 18, Atypoides gertschi Coyle (male: 17, dorsolateral view of chelicerae; 18, ventral view of spinnerets, arrow indicates third spinneret). 19 – 20, Antrodiaetus ashlandensis n. sp. (male: 19, dorsolateral view of chelicerae; 20, ventral view of spinnerets). 21, Antrodiaetus montanus (Chamberlin & Ivie) (male: dorsolateral view of chelicerae, insert shows dorsal view of chelicera with even coat of setae on middle portion). Not to scale.

FIGURES 22 – 33. Genital plates of males. 22 – 23, Antrodiaetus ashlandensis n. sp.; 24 – 25, Antrodiaetus coylei n. sp.; 26 – 27, Antrodiaetus effeminatus n. sp.; 28 – 29, Antrodiaetus metapacificus n. sp.; 30, Antrodiaetus montanus (Chamberlin & Ivie); 31, Antrodiaetus occultus Coyle; 32, Antrodiaetus pacificus (Simon); 33, Antrodiaetus pugnax (Chamberlin). Inserts emphasize sclerotized regions. Scale line = 0.5 mm.

FIGURES 34 – 37. Ectal view of male left chelicera. 34, Antrodiaetus ashlandensis n. sp.; 35, Antrodiaetus coylei n. sp.; 36, Antrodiaetus effeminatus n. sp.; 37, Antrodiaetus metapacificus n. sp. Scale lines = 0.5 mm.

FIGURES 38 – 41. Male left tibia I and metatarsus I. 38 – 39 Antrodiaetus ashlandensis n. sp. (38, prolateral view; 39, ventral view). 40 – 41, Antrodiaetus coylei n. sp. (40, prolateral view; 41, ventral view). Scales = 0.5 mm in 0.1 mm divisions.

FIGURES 49 – 52. Prolateral view of entire palp (left) and view of tip after palp rotated 90 ° on longitudinal axis of distal half of inner conductor sclerite. 49, Antrodiaetus ashlandensis n. sp.; 50, Antrodiaetus coylei n. sp.; 51, Antrodiaetus effeminatus n. sp.; 52, metapacificus n. sp. Scale lines = 0.1 mm.

FIGURES 47, 48. Male left leg I, prolateral view of tibia, metatarsus, tarsus. 47, Antrodiaetus occultus Coyle; 48, Antrodiaetus pugnax (Chamberlin). Scale line = 0.5 mm.